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PE Dynamic [BGP]

This document explains the configuration and principles of BGP routing on PE devices. Similar to CE devices, BGP on PE devices in a service provider's network provides scalability, reliability, and efficient traffic management.

The CE BGP routing documentation is useful for understanding BGP concepts and configuration. The basics are almost the same.

Link to CE BGP Documentation: CE BGP Document

Basic Description​

BGP routing on PE devices exchanges information between the service provider and the customer network. This enables PE devices to learn and advertise network reachability, which ensures traffic flow and network stability. The main aspects of PE BGP configuration include:

  • Autonomous System (AS) Management: PE devices operate within the service provider's network. The AS number is required for proper routing.
  • Route Reflectors and Confederation: In larger networks, route reflectors or confederations are used to simplify IBGP.
  • Policy-Based Routing Integration: PE devices use BGP with policy-based routing to enforce traffic and SLA rules.
  • VPN Routing and Forwarding (VRF): For VPN services, BGP is used to distribute VPN routes, with VRFs isolating customer routing domains within the PE device.

PE BGP Configuration (Conceptual Analogy to CE BGP)​

The basic parameters are the same as CE BGP.

Field (Conceptual)Description (Analogous to CE)
Router IDA unique identification number in the BGP AS for the PE router.
AS NumberThe autonomous system number of the service provider's network.
Neighbor ConfigurationBGP reveals the IP and AS numbers of peers.
Network AdvertisementThe PE device decides which network it will advertise to its peers.
Route Filtering/PolicyUse route maps, prefix lists, and AS path filters to control routing.
VRF ConfigurationVPN routing is done by associating BGP instances with a specific VRF.